AD FAA-2015-1937

We are superseding airworthiness directive (AD) 2014-02-08 for Agusta Model A109C, A109S, A109K2, A109E, and AW109SP helicopters. AD 2014-02-08 required inspecting the lock wires securing the tail rotor (T/R) duplex bearing locking nut (locking nut) to determine whether any lock wires are missing or damaged. This AD retains some of the requirements of AD 2014-02-08 but removes the terminating action, expands the applicability, and adds a daily pilot check. This AD was prompted by reports of loosening T/R locking nuts. These actions are intended to prevent failure of the T/R and subsequent loss of control of the helicopter.